public static void exampleList(List <ForeignCurrencyAccount> list)
        {
            Address address1 = new Address("FirstStreet", 1, "FirstCity", 12345);
            Client  client1  = new Client("Ed", "Small", 12345678910, address1);
            ForeignCurrencyAccount account1 = new ForeignCurrencyAccount(1200, client1, 3, Currency.EURO);

            Address address2 = new Address("SecondStreet", 1, "SecondCity", 23456);
            Client  client2  = new Client("Jim", "Big", 54345678910, address2);
            ForeignCurrencyAccount account2 = new ForeignCurrencyAccount(400, client2, 4, Currency.USD);

            list.Add(account1);
            list.Add(account2);
        }
        public static void addForeignAccount(List <ForeignCurrencyAccount> ForeignCurrencyAccountsList, ref int idNumber)
        {
            ForeignCurrencyAccount nextAccount = new ForeignCurrencyAccount();

            nextAccount.setAccountDetails(ref idNumber);

            foreach (ForeignCurrencyAccount account in ForeignCurrencyAccountsList)
            {
                if (account.AccountOwner.Pesel == nextAccount.AccountOwner.Pesel)
                {
                    Console.WriteLine("Error. Client with " + nextAccount.AccountOwner.Pesel + " PESEL has already had Current Accout.");
                    break;
                }
                else
                {
                    ForeignCurrencyAccountsList.Add(nextAccount);
                    Console.WriteLine("Account has been created.");
                    break;
                }
            }
        }